Hybrid drive device

ABSTRACT

The present invention relates to a hybrid drive device including a first shaft coupled to an internal combustion engine, a rotary electric machine, a second shaft disposed coaxially with the first shaft and coupled to the rotary electric machine and a speed change mechanism, a clutch is provided to switch on and off transfer of a drive force between the first shaft and the second shaft, and a case houses the first shaft, the second shaft, the rotary electric machine, and the clutch. A rotor of the rotary electric machine is fixed to an outer peripheral portion of the clutch housing. A first seal mechanism is disposed in contact with an outer peripheral surface of the large diameter portion of the second axially projecting portion and the inner peripheral surface of the first axially projecting portion, and side by side with the first support mechanism in the axial direction.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2010-081513 filed on Mar. 31, 2010 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a hybrid drive device including a first shaft drivably coupled to an internal combustion engine, a rotary electric machine, a second shaft disposed coaxially with the first shaft and drivably coupled to the rotary electric machine and a speed change mechanism, a clutch provided to switch on and off transfer of a drive force between the first shaft and the second shaft, and a case that houses the first shaft, the second shaft, the rotary electric machine, and the clutch.

DESCRIPTION OF THE RELATED ART

A device disclosed in Japanese Patent Application Publication No. 2005-112351 below, for example, is already known as a hybrid drive device including a first shaft drivably coupled to an internal combustion engine, a rotary electric machine, a second shaft disposed coaxially with the first shaft and drivably coupled to the rotary electric machine and a speed change mechanism, a clutch provided to switch on and off transfer of a drive force between the first shaft and the second shaft, and a case that houses the first shaft, the second shaft, the rotary electric machine, and the clutch. In the hybrid drive device, as shown in FIGS. 1 and 2 of Japanese Patent Application Publication No. 2005-112351, a first shaft drivably coupled to an internal combustion engine (internal combustion engine 2 according to Japanese Patent Application Publication No. 2005-112351; the same applies hereinafter) and a second shaft (transmission input shaft 7) drivably coupled to the first shaft and a speed change mechanism are selectively drivably coupled to each other via a clutch (separation clutch 4), and a rotary electric machine (electric motor 5) is drivably coupled to the second shaft to rotate together with the second shaft. Such a configuration is well known as a configuration that can implement a so-called one-motor parallel type hybrid drive device. In the device, for example, the vehicle can be started to run using torque of the rotary electric machine with the clutch in the disengaged state, and after the vehicle speed is raised to a certain level, the vehicle can be run using torque of the internal combustion engine and the rotary electric machine with the clutch in the engaged state.

SUMMARY OF THE INVENTION

When the clutch switches on and off transfer of a drive force, in general, a plurality of friction plates provided in the clutch are caused to slip over each other, and thus produce heat. In order to suitably maintain the performance of the clutch, it is desired to effectively cool the plurality of friction plates which produce heat. As a solution, it is considered to cool the plurality of friction plates of the clutch with a large amount of oil by filling the surrounding area of the clutch with oil sealed in the hybrid drive device for the purpose of lubrication, cooling, or the like, for example. In this case, it is preferable, from the viewpoint of simplifying the configuration of the device, to effectively utilize oil for cooling the plurality of friction plates to also lubricate bearings and so forth generally provided in the hybrid drive device. In particular, it is preferable to provide a clutch housing member in order to achieve a configuration in which the surrounding area of the clutch is filled with oil to effectively cool the clutch. In this event, it is preferable to also lubricate support mechanisms, such as bearings, that rotatably support the clutch housing member so that the clutch housing member is appropriately and smoothly supported with respect to other members such as the case.

When the rotary electric machine outputs torque, meanwhile, the rotary electric machine produces heat due to occurrence of so-called copper loss, iron loss, and so forth. In order to suitably maintain the performance of the rotary electric machine, it is desired to appropriately cool the rotary electric machine which produces heat. However, foreign matter such as minute metal pieces may mix into oil sealed in the device, and in the case where such foreign matter adheres to the rotary electric machine, the rotary electric machine which requires precise control may be affected. Therefore, the rotary electric machine is preferably cooled by a cooling structure (an air-cooling structure) that utilizes a wind received while the vehicle is running or the like, rather than a cooling structure (an oil-cooling structure) that utilizes oil sealed in the device.

Further, the axial dimension of the entire device is preferably as small as possible.

However, no solutions to such issues are provided in Japanese Patent Application Publication No. 2005-112351.

Thus, there is desired a hybrid drive device in which a clutch and a rotary electric machine can be individually cooled appropriately, a clutch housing member provided to effectively cool the clutch can be supported appropriately and smoothly, and further the axial dimension of the entire device can be reduced.

The present invention provides a hybrid drive device including: a first shaft drivably coupled to an internal combustion engine; a rotary electric machine; a second shaft disposed coaxially with the first shaft and drivably coupled to the rotary electric machine and a speed change mechanism; a clutch provided to switch on and off transfer of a drive force between the first shaft and the second shaft; a case that houses the first shaft, the second shaft, the rotary electric machine, and the clutch; a clutch housing which houses the clutch by covering both sides of the clutch in an axial direction and an outer side of the clutch in a radial direction, which is drivably coupled to the second shaft, and inside which an oil chamber filled with oil is formed; and a first support mechanism that supports the clutch housing in the radial direction and the axial direction so as to be rotatable with respect to the case, and a first seal mechanism that oil-tightly seals an area between the case and the clutch housing, the first support mechanism and the first seal mechanism being provided on one side in the axial direction with respect to the clutch housing. In the hybrid drive device, a rotor of the rotary electric machine is fixed to an outer peripheral portion of the clutch housing, the case includes a one-side support wall portion provided on one side in the axial direction with respect to the clutch housing to extend radially, and a cylindrical first axially projecting portion projecting from the one-side support wall portion toward the other side in the axial direction, the clutch housing includes a one-side radially extending portion disposed on one side in the axial direction with respect to the clutch to extend radially, and a cylindrical second axially projecting portion projecting from the one-side radially extending portion toward one side in the axial direction, the second axially projecting portion is formed in a stepped shape in which a portion with a large outside diameter is formed on the other side in the axial direction and a portion with a small outside diameter is formed on one side in the axial direction, the first support mechanism is disposed in contact with an outer peripheral surface of the small diameter portion of the second axially projecting portion and an inner peripheral surface of the first axially projecting portion, and the first seal mechanism is disposed in contact with an outer peripheral surface of the large diameter portion of the second axially projecting portion and the inner peripheral surface of the first axially projecting portion, and side by side with the first support mechanism in the axial direction.

According to the above characteristic configuration, the oil chamber formed inside the clutch housing is filled with oil, and thus the clutch housed in the clutch housing can be effectively cooled with a large amount of oil. The clutch housing can be supported in the radial direction and the axial direction so as to be rotatable with respect to the case on one side in the axial direction by the first support mechanism, which is disposed in contact with the outer peripheral surface of the small diameter portion of the second axially projecting portion and the inner peripheral surface of the first axially projecting portion. The first support mechanism can be lubricated by effectively utilizing oil for cooling the clutch, by appropriately guiding oil filling the oil chamber in the clutch housing to an area outside the clutch housing on one side in the axial direction. An area between the case and the clutch housing can be sealed oil-tightly on the other side in the axial direction with respect to first support mechanism by the first seal mechanism, which is disposed in contact with the outer peripheral surface of the large diameter portion of the second axially projecting portion and the inner peripheral surface of the first axially projecting portion. This prevents oil having lubricated the first support mechanism from reaching the rotary electric machine, which is fixed to the outer peripheral portion of the clutch housing, and thus an air-cooling structure that utilizes a wind received while the vehicle is running or the like can be employed as a cooling structure for the rotary electric machine. Accordingly, the rotary electric machine can be cooled appropriately without being significantly affected by foreign matter or the like. Further, the rotor of the rotary electric machine is fixed to the outer peripheral portion of the clutch housing, and thus the axial dimension of the entire device can be reduced compared to a case where the rotary electric machine and the clutch housing are disposed side by side with each other in the axial direction, for example.

Thus, according to the above characteristic configuration, it is possible to provide a hybrid drive device in which a clutch and a rotary electric machine can be individually cooled appropriately, a clutch housing provided to effectively cool the clutch can be supported appropriately and smoothly, and further the axial dimension of the entire device can be reduced.

Preferably, the one-side radially extending portion is formed in a shape in which a radially inner end portion is positioned on the other side in the axial direction with respect to a radially outer end portion, and one or both of the first support mechanism and the first seal mechanism are disposed to overlap the one-side radially extending portion in the axial direction.

The term “overlap” in a certain direction as used herein in regard to the arrangement of two members refers to a state in which the two members are at least partially disposed at the same position in the certain direction.

According to the configuration, the axial dimension of the entire device can be reduced by at least an amount of overlap between the first seal mechanism and the one-side radially extending portion in the axial direction, compared to a case where the one-side radially extending portion is formed in the shape of a flat plate extending radially and the second axially projecting portion projects toward one side in the axial direction from the one-side radially extending portion formed in such a plate shape, for example. In the case where both the first seal mechanism and the first support mechanism are disposed to overlap the one-side radially extending portion in the axial direction, the axial dimension of the entire device can be further reduced.

Preferably, the hybrid drive device further includes a second support mechanism that supports the clutch housing in the radial direction and the axial direction so as to be rotatable with respect to the case, and a second seal mechanism that oil-tightly seals an area between the case and the clutch housing, the second support mechanism and the second seal mechanism being provided on the other side in the axial direction with respect to the clutch housing. In the hybrid drive device, the case includes an other-side support wall portion provided on the other side in the axial direction with respect to the clutch housing to extend radially, and a cylindrical third axially projecting portion projecting from the other-side support wall portion toward one side in the axial direction, the clutch housing includes an other-side radially extending portion disposed on the other side in the axial direction with respect to the clutch to extend radially, and a cylindrical fourth axially projecting portion projecting from the other-side radially extending portion toward the other side in the axial direction, the fourth axially projecting portion is formed in a stepped shape in which a portion with a large outside diameter is formed on one side in the axial direction and a portion with a small outside diameter is formed on the other side in the axial direction, the second support mechanism is disposed in contact with an outer peripheral surface of the small diameter portion of the fourth axially projecting portion and an inner peripheral surface of the third axially projecting portion, and the second seal mechanism is disposed in contact with an outer peripheral surface of the large diameter portion of the fourth axially projecting portion and the inner peripheral surface of the third axially projecting portion, and side by side with the second support mechanism in the axial direction.

According to the configuration, the clutch housing can be supported in the radial direction and the axial direction so as to be rotatable with respect to the case on the other side in the axial direction by the second support mechanism, which is disposed in contact with the outer peripheral surface of the small diameter portion of the fourth axially projecting portion and the inner peripheral surface of the third axially projecting portion. An area between the case and the clutch housing can be sealed oil-tightly on one side in the axial direction with respect to the second support mechanism by the second seal mechanism, which is disposed in contact with the outer peripheral surface of the large diameter portion of the fourth axially projecting portion and the inner peripheral surface of the third axially projecting portion. This prevents oil supplied to the second support mechanism to lubricate the second support mechanism from reaching the rotary electric machine fixed to the outer peripheral portion of the clutch housing.

Preferably, the other-side radially extending portion is formed in a shape in which a radially inner end portion is positioned on one side in the axial direction with respect to a radially outer end portion, and one or both of the second support mechanism and the second seal mechanism are disposed to overlap the other-side radially extending portion in the axial direction.

According to the configuration, the axial dimension of the entire device can be reduced by at least an amount of overlap between the second seal mechanism and the other-side radially extending portion in the axial direction, compared to a case where the other-side radially extending portion is formed in the shape of a flat plate extending radially and the fourth axially projecting portion projects toward the other side in the axial direction from the other-side radially extending portion formed in such a plate shape, for example. In the case where both the second seal mechanism and the second support mechanism are disposed to overlap the other-side radially extending portion in the axial direction, the axial dimension of the entire device can be further reduced.

Preferably, the hybrid drive device further includes a second support mechanism that supports the clutch housing in the radial direction and the axial direction so as to be rotatable with respect to the case, and a second seal mechanism that oil-tightly seals an area between the case and the clutch housing, the second support mechanism and the second seal mechanism being provided on the other side in the axial direction with respect to the clutch housing. In the hybrid drive device, the case includes an other-side support wall portion provided on the other side in the axial direction with respect to the clutch housing to extend radially, and a cylindrical third axially projecting portion projecting from the other-side support wall portion toward one side in the axial direction, the clutch housing includes an other-side radially extending portion disposed on the other side in the axial direction with respect to the clutch to extend radially, and a cylindrical fourth axially projecting portion projecting from the other-side radially extending portion toward the other side in the axial direction, the other-side radially extending portion includes a first circular plate portion provided with the fourth axially projecting portion, a second circular plate portion disposed radially outwardly of the first circular plate portion and offset on the other side in the axial direction with respect to the first circular plate portion, and a stepped cylindrical portion formed to couple the first circular plate portion and the second circular plate portion to each other, the second support mechanism is disposed in contact with an outer peripheral surface of the fourth axially projecting portion and an inner peripheral surface of the third axially projecting portion, and the second seal mechanism is disposed in contact with an outer peripheral surface of the third axially projecting portion and an inner peripheral surface of the stepped cylindrical portion to overlap the second support mechanism in the axial direction.

According to the configuration, the clutch housing can be supported in the radial direction and the axial direction so as to be rotatable with respect to the case on the other side in the axial direction by the second support mechanism, which is disposed in contact with the outer peripheral surface of the fourth axially projecting portion and the inner peripheral surface of the third axially projecting portion. An area between the case and the clutch housing can be sealed oil-tightly on the radially outer side with respect to the second support mechanism by the second seal mechanism, which is disposed in contact with the outer peripheral surface of the third axially projecting portion and the inner peripheral surface of the stepped cylindrical portion. This prevents oil supplied to the second support mechanism to lubricate the second support mechanism from reaching the rotary electric machine fixed to the outer peripheral portion of the clutch housing.

According to the configuration, in addition, both of the second seal mechanism and the second support mechanism are disposed to overlap the stepped cylindrical portion forming a part of the other-side radially extending portion in the axial direction, and thus the axial dimension of the entire device can be reduced.

Preferably, a plurality of friction plates provided in the clutch are disposed radially outwardly of the first seal mechanism and the second seal mechanism.

In the clutch provided to switch on and off transfer of a drive force between the first shaft and the second shaft disposed coaxially with each other, in general, the plurality of friction plates provided in the clutch are disposed side by side with each other in the axial direction so as to be slidable with respect to each other in the axial direction.

According to the configuration, the plurality of friction plates can be disposed appropriately in a space that is provided radially outwardly of the first seal mechanism and the second support mechanism and that is large in the axial direction.

Preferably, the clutch includes a piston that presses the plurality of friction plates against each other, and the second seal mechanism is disposed to overlap the piston in the axial direction.

According to the configuration, the second seal mechanism is disposed to overlap the piston housed in the clutch housing in the axial direction, and thus the second seal mechanism can be disposed to overlap the clutch housing in the axial direction. Accordingly, the axial direction of the entire device can be further reduced.

Preferably, the hybrid drive device includes a coupling member extending radially to couple the first shaft and a clutch hub of the clutch to each other, and a third support mechanism and a fourth support mechanism disposed in contact with a surface of the coupling member on one side in the axial direction and a surface of the coupling member on the other side in the axial direction, respectively, to support the coupling member and the clutch housing so as to be relatively rotatable with respect to each other. In the hybrid drive device, the coupling member includes a shaft-side coupling portion extending radially outward from the first shaft, and a hub-side coupling portion forming a part of the clutch hub and extending radially inward, the hub-side coupling portion is coupled to the shaft-side coupling portion with the hub-side coupling portion in contact with a notched groove formed in a radially outer end portion of the shaft-side coupling portion from one side in the axial direction, the one-side radially extending portion includes a cylindrical axially retracted surface formed to be continuous from a surface of the one-side radially extending portion on the other side in the axial direction and to be retracted toward one side in the axial direction, the third support mechanism is positioned in the radial direction by the axially retracted surface, and the fourth support mechanism is disposed radially outwardly of the third support mechanism, and positioned in the radial direction by a radially outer end of the shaft-side coupling portion.

According to the configuration, the shaft-side coupling portion and the hub-side coupling portion can be coupled to each other with the shaft-side coupling portion supporting the hub-side coupling portion in the axial direction from the other side in the axial direction in the notched groove of the shaft-side coupling portion. In this event, the notched groove can be formed relatively easily and precisely by forming the notched groove in the shaft-side coupling portion extending radially outward from the first shaft, which is a shaft member that is generally easy to machine.

The third support mechanism can be positioned in the radial direction by the axially retracted surface formed in the one-side radially extending portion, and the fourth support mechanism can be positioned in the radial direction by the radially outer end of the shaft-side coupling portion. Further, the axial dimension of the entire device can be reduced compared to a case where the third support mechanism and the fourth support mechanism are disposed side by side with each other in the axial direction on both sides of the shaft-side coupling portion in the axial direction or the like, for example.

Preferably, the hybrid drive device includes a damper device disposed on one side in the axial direction with respect to the one-side support wall portion and interposed between the first shaft and the internal combustion engine. In the hybrid drive device, the damper device is disposed to overlap in the axial direction a coil end portion projecting in the axial direction from a stator of the rotary electric machine.

According to the configuration, rotation output from the internal combustion engine can be transferred to the first shaft with the damper device attenuating torsional vibration of the rotation output from the internal combustion engine. With the damper device disposed to overlap the coil end portion of the rotary electric machine in the axial direction, the axial dimension of the entire device can be further reduced by an amount of overlap between these components in the axial direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the schematic configuration of a hybrid drive device according to a first embodiment;

FIG. 2 is a cross-sectional view showing a part of the hybrid drive device according to the first embodiment;

FIG. 3 is a cross-sectional view showing an essential portion of the hybrid drive device according to the first embodiment; and

FIG. 4 is a cross-sectional view showing an essential portion of a hybrid drive device according to a second embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS 1. First Embodiment

A first embodiment of the present invention will be described with reference to the drawings. A hybrid drive device 1 is a drive device for a hybrid vehicle that uses one or both of an internal combustion engine E and a rotary electric machine MG as a drive force source for the vehicle. The hybrid drive device 1 is formed as a so-called one-motor parallel type hybrid drive device.

As shown in FIG. 1, the hybrid drive device 1 according to the embodiment includes an input shaft I drivably coupled to the internal combustion engine E, the rotary electric machine MG, an intermediate shaft M drivably coupled to the rotary electric machine MG and a speed change mechanism TM, a clutch CL provided to switch on and off transfer of a drive force between the input shaft I and the intermediate shaft M, and a case 2 that houses the input shaft I, the intermediate shaft M, the clutch CL, and so forth. The hybrid drive device 1 according to the embodiment configured as described above is characterized in including a clutch housing CH that houses the clutch CL with oil filling the inside of the clutch housing CH (see FIG. 2), and in a rotatably supporting structure and a sealing structure for the clutch housing CH with respect to the case 2.

That is, as shown in FIGS. 2 and 3, the hybrid drive device 1 includes the clutch housing CH which houses the clutch CL by covering both sides of the clutch CL in the axial direction and the outer side of the clutch CL in the radial direction, which is drivably coupled to the intermediate shaft M, and inside which an oil circulation chamber 38 filled with oil is formed. The hybrid drive device 1 also includes a first bearing 51 that supports the clutch housing CH in the radial direction and the axial direction so as to be rotatable with respect to the case 2, and a first seal member 61 that oil-tightly seals an area between the case 2 and the clutch housing CH. The first bearing 51 and the first seal member 61 are provided on one side in the axial direction with respect to the clutch housing CH. A rotor Ro of the rotary electric machine MG is fixed to the outer peripheral portion of the clutch housing CH. The case 2 includes a first support wall 4 provided on one side in the axial direction with respect to the clutch housing CH to extend radially, and a cylindrical axially projecting portion 5 projecting from the first support wall 4 toward the other side in the axial direction. The clutch housing CH includes a one-side radially extending portion 41 disposed on one side in the axial direction with respect to the clutch CL to extend radially, and a cylindrical axially projecting portion 42 projecting from the one-side radially extending portion 41 toward one side in the axial direction. The axially projecting portion 42 is formed in a stepped shape in which a large diameter portion is formed on the other side in the axial direction and a small diameter portion is formed on one side in the axial direction. Based on such a configuration, the first bearing 51 is disposed in contact with the outer peripheral surface of the small diameter portion of the axially projecting portion 42 and the inner peripheral surface of the axially projecting portion 5, and the first seal member 61 is disposed in contact with the outer peripheral surface of the large diameter portion of the axially projecting portion 42 and the inner peripheral surface of the axially projecting portion 5, and side by side with the first bearing 51 in the axial direction. The combination of such characteristic configurations provides the hybrid drive device 1 in which the clutch CL and the rotary electric machine MG can be individually cooled appropriately, the clutch housing CH provided to effectively cool the clutch CL can be supported appropriately and smoothly, and further the axial dimension of the entire device can be reduced. The hybrid drive device 1 according to the embodiment will be described in detail below.

1-1. Overall Configuration of Hybrid Drive Device

First, the overall configuration of the hybrid drive device 1 according to the embodiment will be described. As shown in FIG. 1, the hybrid drive device 1 includes the input shaft I drivably coupled to the internal combustion engine E serving as a first drive force source of the vehicle, the rotary electric machine MG serving as a second drive force source of the vehicle, the speed change mechanism TM, the intermediate shaft M drivably coupled the rotary electric machine MG and drivably coupled to the speed change mechanism TM, and an output shaft O drivably coupled to wheels W. The hybrid drive device 1 also includes the clutch CL provided to switch on and off transfer of a drive force between the input shaft I and the intermediate shaft M, a counter gear mechanism C, and an output differential gear device DF. These components are housed in the case 2 serving as a drive device case. In the embodiment, the input shaft I is equivalent to the “first shaft” according to the present invention, and the intermediate shaft M is equivalent to the “second shaft” according to the present invention.

The term “drivably coupled” refers to a state in which two rotary elements are coupled to each other in such a way that allows transfer of a drive force, which includes a state in which the two rotary elements are coupled to each other to rotate together with each other, and a state in which the two rotary elements are coupled to each other via one or two or more transmission members in such a way that allows transfer of a drive force. Examples of such transmission members include various members that transfer rotation at an equal speed or a changed speed, such as a shaft, a gear mechanism, a belt, and a chain. The term “drive force” is used as a synonym for torque. The term “rotary electric machine” refers to any of a motor (electric motor), a generator (electric generator), and a motor generator that functions as both a motor and a generator as necessary.

The internal combustion engine E is a device driven by combusting fuel inside the engine to take out motive power. Various engines known in the art such as a gasoline engine and a diesel engine, for example, may be used as the internal combustion engine E. In the embodiment, an internal combustion engine output shaft Eo of the internal combustion engine E, such as a crankshaft, is drivably coupled to the input shaft I via a damper D. The input shaft I is drivably coupled to the rotary electric machine MG and the intermediate shaft M via the clutch CL. The input shaft I is selectively drivably coupled to the rotary electric machine MG and the intermediate shaft M through the clutch CL. When the clutch CL is in the engaged state, the internal combustion engine E and the rotary electric machine MG are drivably coupled to each other via the input shaft I. When the clutch CL is in the disengaged state, the internal combustion engine E and the rotary electric machine MG are separated from each other.

The rotary electric machine MG includes a stator St and the rotor Ro, and can function both as a motor (electric motor) that is supplied with electric power to generate motive power and as a generator (electric generator) that is supplied with motive power to generate electric power. Therefore, the rotary electric machine MG is electrically connected to an electricity accumulation device (not shown). In the embodiment, a battery is used as the electricity accumulation device. A capacitor or the like may be suitably used as the electricity accumulation device. The rotary electric machine MG receives electric power from the battery for power running, or supplies electric power generated using torque output from the internal combustion engine E or an inertial force of the vehicle to the battery to accumulate the electric power. The rotor Ro of the rotary electric machine MG is drivably coupled to the intermediate shaft M to rotate together with the intermediate shaft M. The intermediate shaft M serves as an input shaft of the speed change mechanism TM (transmission input shaft).

The speed change mechanism TM is a device that changes the speed of rotation of the intermediate shaft M with a predetermined speed ratio to transfer the rotation to a transmission output gear G. In the embodiment, an automatic speed change mechanism including single-pinion type and Ravigneaux type planetary gear mechanisms and a plurality of engagement devices such as a clutch, a brake, and a one-way clutch to switchably provide a plurality of shift speeds with different speed ratios is used as the speed change mechanism TM. An automatic speed change mechanism with other specific configurations, an automatic continuously variable speed change mechanism with continuously variable speed ratios, a manual stepped speed change mechanism that switchably provides a plurality of shift speeds with different speed ratios, or the like may also be used as the speed change mechanism TM. The speed change mechanism TM changes the speed of rotation of the intermediate shaft M and converts torque with a predetermined speed ratio for each timing to transfer the rotation and the torque to the transmission output gear G.

The counter gear mechanism C transfers rotation and torque of the transmission output gear G to the side of the wheels W. The counter gear mechanism C includes a counter shaft Cs, a first gear C1, and a second gear C2. The first gear C1 meshes with the transmission output gear G. The second gear C2 meshes with a differential input gear Di of the output differential gear device DF. The output differential gear device DF splits rotation and torque of the differential input gear Di to transfer the split rotation and torque to the plurality of wheels W. In the embodiment, the output differential gear device DF is formed by a differential gear mechanism that uses a plurality of bevel gears meshing with each other, and splits torque transferred to the differential input gear Di via the second gear C2 of the counter gear mechanism C to transfer the split torque to the two left and right wheels W via respective output shafts O. This allows the hybrid drive device 1 to transfer torque of one or both of the internal combustion engine E and the rotary electric machine MG to the wheels W to run the vehicle.

In the hybrid drive device 1 according to the embodiment, the input shaft I and the intermediate shaft M are disposed coaxially with each other, and the counter shaft Cs and the output shafts O are disposed in parallel with each other and non-coaxially with the input shaft I and the intermediate shaft M. Such a configuration is suitable as a configuration of the hybrid drive device 1 to be mounted on FF (Front-Engine Front-Drive) vehicles, for example:

1-2. Configuration of Various Sections of Hybrid Drive Device

Next, the configuration of various sections of the hybrid drive device 1 according to the embodiment will be described. As shown in FIG. 2, the case 2 includes a case peripheral wall 3 that covers respective outer peripheries of components housed in the case 2 such as the rotary electric machine MG and the speed change mechanism TM, the first support wall 4 which blocks an opening of the ease peripheral wall 3 on one side in the axial direction (on the side of the internal combustion engine E and on the right side in FIG. 2; the same applies hereinafter), and a second support wall 7 provided on the other side in the axial direction (on the side away from the internal combustion engine E and on the left side in FIG. 2; the same applies hereinafter) with respect to the first support wall 4 and disposed between the rotary electric machine MG and the speed change mechanism TM in the axial direction. Although not shown, the case 2 further includes an end portion support wall that blocks an end portion of the case peripheral wall 3 on the other side in the axial direction.

The first support wall 4 is shaped to extend at least in the radial direction.

In the embodiment, the first support wall 4 extends in the radial direction and the circumferential direction. A through hole in the axial direction is formed in the first support wall 4, and the input shaft I, which is inserted through the through hole, penetrates through the first support wall 4 to be inserted into the case 2. The first support wall 4 is coupled to the axially projecting portion 5 which has the shape of a cylinder (boss) projecting toward the other side in the axial direction. The axially projecting portion 5 is integrally coupled to the first support wall 4. In the embodiment, the first support wall 4 is a wall portion having a curved shape like a dish that is convex toward the other side in the axial direction such that a radially inner portion is positioned on the other side in the axial direction with respect to a radially outer portion at a portion of the first support wall 4 through which the input shaft I penetrates. The first support wall 4 is disposed on one side in the axial direction with respect to the clutch CL. More specifically, the first support wall 4 is disposed adjacently with a predetermined clearance on one side in the axial direction with respect to the clutch housing CH. An oil passage forming member 71, inside which an oil discharge passage 72 is formed, is attached to the first support wall 4 to extend along the radial direction. In the embodiment, the first support wall 4 is equivalent to the “one-side support wall portion” according to the present invention, and the axially projecting portion 5 is equivalent to the “first axially projecting portion” according to the present invention.

The second support wall 7 is shaped to extend at least in the radial direction. In the embodiment, the second support wall 7 extends in the radial direction and the circumferential direction. A through hole in the axial direction is formed in the second support wall 7, and the intermediate shaft M, which is inserted through the through hole, penetrates through the second support wall 7. The second support wall 7 is coupled to an axially projecting portion 8 which has the shape of a cylinder (boss) projecting toward one side in the axial direction. The axially projecting portion 8 is integrally coupled to the second support wall 7. The second support wall 7 is disposed on the other side in the axial direction with respect to the clutch CL. More specifically, the second support wall 7 is disposed adjacently with a predetermined clearance on the other side in the axial direction with respect to the clutch housing CH. An oil pump 18 is housed in a pump chamber formed inside the second support wall 7. In the embodiment, the oil pump 18 is an internal gear pump having an inner rotor and an outer rotor. The inner rotor of the oil pump 18 is drivably coupled (here, splined), at a radially central portion of the oil pump 18, to the clutch housing CH to rotate together with the clutch housing CH. As the clutch housing CH rotates, the oil pump 18 discharges oil to generate a hydraulic pressure for supplying oil to the clutch CL, the speed change mechanism TM, and so forth. An oil passage is formed inside each of the second support wall 7, the intermediate shaft M, and so forth. Oil discharged from the oil pump 18 flows through a hydraulic pressure control device (not shown) and these oil passages to be supplied to respective portions to which oil should be supplied. In the embodiment, the second support wall 7 is equivalent to the “other-side support wall portion” according to the present invention, and the axially projecting portion 8 is equivalent to the “third axially projecting portion” according to the present invention.

The input shaft I is a shaft used to input torque of the internal combustion engine E to the hybrid drive device 1. An end portion of the input shaft I on one side in the axial direction is drivably coupled to the internal combustion engine E. Here, the input shaft I is disposed to penetrate through the first support wall 4. As shown in FIG. 2, the input shaft I is drivably coupled to the internal combustion engine output shaft Eo of the internal combustion engine E via the damper D at a position on one side in the axial direction with respect to the first support wall 4 to rotate together with the internal combustion engine output shaft Eo. The damper D is a device that transfers rotation of the internal combustion engine output shaft Eo to the input shaft I while attenuating torsional vibration of the internal combustion engine output shaft Eo. Various dampers known in the art may be used as the damper D. In the embodiment, the damper D includes a plurality of coil springs disposed along the circumferential direction. The damper D is integrally fixed to a drive plate DP fixed to the internal combustion engine output shaft Eo, and splined to the input shaft I. The damper D is formed as a whole to be smaller in diameter than the drive plate DP, and disposed on the other side in the axial direction with respect to the drive plate DP. A third seal member 63 is disposed between the input shaft I and the first support wall 4 to suppress leakage of oil to one side in the axial direction (to the side of the damper D and the internal combustion engine E) by liquid-tightly sealing an area between the input shaft I and the first support wall 4.

In the embodiment, an axial end hole portion 12 extending in the axial direction is formed in a radially inner portion of an end portion of the input shaft I on the other side in the axial direction. An end portion of the intermediate shaft M on one side in the axial direction is inserted in the axial direction into the axial end hole portion 12. A flange portion 11 extending radially from the input shaft I is formed at an end portion of the input shaft I on the other side in the axial direction. The flange portion 11 is formed integrally with the input shaft I. In the clutch housing CH, the flange portion 11 is coupled to a clutch hub 21 of the clutch CL housed in the clutch housing CH. A second bearing 52 is disposed on one side in the axial direction with respect to the flange portion 11. A third bearing 53 is disposed radially outwardly of the flange portion 11 and on the other side in the axial direction with respect to the clutch hub 21 of the clutch CL. With such a positional relationship, the third bearing 53 is disposed radially outwardly of the second bearing 52. In the embodiment, the second bearing 52 is equivalent to the “third support mechanism” according to the present invention, and the third bearing 53 is equivalent to the “fourth support mechanism” according to the present invention.

The intermediate shaft M is a shaft used to input one or both of torque of the rotary electric machine MG and torque of the internal combustion engine E via the clutch CL to the speed change mechanism TM, and splined to the clutch housing CH. As shown in FIG. 2, the intermediate shaft M is disposed to penetrate through the second support wall 7. As described above, a through hole in the axial direction is formed in a radially central portion of the second support wall 7, and the intermediate shaft M penetrates through the second support wall 7 via the through hole. The intermediate shaft M is supported in the radial direction so as to be rotatable with respect to the second support wall 7. The end portion of the intermediate shaft M on one side in the axial direction is inserted in the axial direction into the axial end hole portion 12 of the input shaft I. In this event, a predetermined gap is formed between an end surface of the intermediate shaft M on one side in the axial direction and a surface defining the bottom portion of the axial end hole portion 12 of the input shaft I in the axial direction. In the embodiment, a plurality of oil passages including an oil supply passage 15 and an oil discharge passage 16 are formed in a radially inner portion of the intermediate shaft M. The oil supply passage 15 extends in the axial direction in the intermediate shaft M on one side in the axial direction, and extends radially at a predetermined position in the axial direction to open in the outer peripheral surface of the intermediate shaft M so as to communicate with a hydraulic oil chamber 37 of the clutch CL. The oil discharge passage 16 extends in the axial direction at a position that is different in the circumferential direction from that of the oil supply passage 15 in the intermediate shaft M on one side in the axial direction to open in an end surface of the intermediate shaft M on one side in the axial direction.

As described above, the clutch CL is a friction engagement device provided to switch on and off transfer of a drive force between the input shaft I and the intermediate shaft M and to selectively drivably couple the internal combustion engine E and the rotary electric machine MG to each other as described above. In the embodiment, the clutch CL is formed as a wet multi-plate clutch mechanism. As shown in FIG. 3, the clutch CL includes the clutch hub 21, a clutch drum 26, a plurality of friction plates 31, and a piston 36. The clutch hub 21 is coupled to the flange portion 11 of the input shaft I to rotate together with the input shaft I. The clutch drum 26 is coupled to the intermediate shaft M via the clutch housing CH to rotate together with the intermediate shaft M. In the embodiment, the clutch drum 26 has a cylindrical shape, and is formed integrally with the clutch housing CH. The friction plates 31 include hub-side friction plates and drum-side friction plates forming pairs. The hub-side friction plates are supported by the clutch hub 21 from the radially inner side, and held so as not to be relatively rotatable with respect to the clutch hub 21 but to be slidable in the axial direction. The drum-side friction plates are supported by the clutch drum 26 from the radially outer side, and held so as not to be rotatable relative to the clutch drum 26 but to be slidable in the axial direction. The hub-side friction plates and the drum-side friction plates are disposed alternately in the axial direction. A backing plate 32 is held on one side in the axial direction with respect to all the friction plates 31. The backing plate 32 functions as a pressing member when the plurality of friction plates 31 are to be engaged with each other. The backing plate 32 is held by a snap ring so as not to be movable in the axial direction. The piston 36 is disposed on the other side in the axial direction with respect to the plurality of friction plates 31, and urged by a return spring toward the other side in the axial direction.

In the embodiment, the hydraulic oil chamber 37 which is liquid-tight is formed between the clutch housing CH, which is integrated with the clutch drum 26, and the piston 36. The hydraulic oil chamber 37 is supplied with pressurized oil, which has been discharged from the oil pump 18 and adjusted to a predetermined hydraulic pressure by a hydraulic pressure control device (not shown), via the oil supply passage 15 formed in the intermediate shaft M and an oil communication passage 48 formed in the clutch housing CH. When the hydraulic pressure in the hydraulic oil chamber 37 rises to be larger than the urging force of the return spring, the piston 36 moves in the direction of increasing the capacity of the hydraulic oil chamber 37 (in the embodiment, toward one side in the axial direction) to engage the plurality of friction plates 31 with each other in cooperation with the backing plate 32. As a result, torque of the internal combustion engine E transferred from the input shaft I is transferred to the rotary electric machine MG and the intermediate shaft M via the clutch CL. On the other hand, the oil circulation chamber 38 is formed opposite the hydraulic oil chamber 37 with respect to the piston 36. The oil circulation chamber 38 is supplied with pressurized oil, which has been discharged from the oil pump 18 and adjusted to a predetermined hydraulic pressure by a hydraulic pressure control device (not shown), via an oil circulation passage 47 (see FIG. 2) formed in the clutch housing CH.

In the embodiment, as described above, the clutch hub 21 is coupled to the flange portion 11 of the input shaft Ito rotate together with the input shaft I. Here, as shown in FIG. 3, the clutch hub 21 includes a cylindrical portion formed in a cylindrical shape to hold the plurality of hub-side plates, and an annular plate portion 22 formed in the shape of an annular plate extending radially inward from an end portion of the cylindrical portion on one side in the axial direction to support the plurality of hub-side plates and the cylindrical portion in the radial direction. The annular plate portion 22 forming a part of the clutch hub 21 is coupled to the flange portion 11 of the input shaft I to integrally couple the input shaft I and the clutch hub 21 to each other. In the embodiment, the flange portion 11 of the input shaft I is equivalent to the “shaft-side coupling portion” according to the present invention, and the annular plate portion 22 of the clutch hub 21 is equivalent to the “hub-side coupling portion” according to the present invention. In addition, the flange portion 11 and the annular plate portion 22 form the “coupling member” according to the present invention.

In the embodiment, as shown in FIG. 3, a notched groove 11 a is formed in a radially outer end portion of the flange portion 11. The notched groove 11 a is formed in an end portion of the flange portion 11 on one side in the axial direction such that a surface defining the bottom portion of the notched groove 11 a in the radial direction is continuous with a surface of the flange portion 11 on one side in the axial direction. The width of the notched groove 11 a in the axial direction is generally equal to the width of a radially inner end portion of the annular plate portion 22 of the clutch hub 21. The annular plate portion 22 is coupled by welding or the like to the flange portion 11 with the annular plate portion 22 in contact with the notched groove 11 a formed in the flange portion 11 from one side in the axial direction. In the embodiment, the input shaft I and the flange portion 11 extending radially outward from the input shaft I are formed by cutting on a lathe or the like which enables precise machining. Accordingly, the notched groove 11 a can be formed relatively easily and precisely as the input shaft I and the flange portion 11 are formed. On the other hand, the clutch hub 21, which requires low precision compared to the input shaft I and the flange portion 11, is formed by pressing which enables low-cost manufacture.

In the embodiment, the second bearing 52 and the third bearing 53 are disposed in the vicinity of a location where the flange portion 11 and the annular plate portion 22 are coupled to each other. More specifically, the second bearing 52 is disposed in contact with a surface of the flange portion 11 on one side in the axial direction. Further, the second bearing 52 contacts the clutch housing CH (the one-side radially extending portion 41 to be discussed later) on one side in the axial direction. Meanwhile; the third bearing 53 is disposed in contact with a surface of the annular plate portion 22 on the other side in the axial direction. Further, the third bearing 53 contacts the clutch housing CH (an other-side radially extending portion 45 to be discussed later) on the other side in the axial direction. In the embodiment, a thrust washer that can receive an axial load is used as each of the second bearing 52 and the third bearing 53. This allows the flange portion 11 and the annular plate portion 22, which are integrally coupled to each other, and the clutch housing CH to be supported via the second bearing 52 and the third bearing 53 so as to be relatively rotatable with respect to each other. Although not described in detail here, a plurality of radial grooves extending in the radial direction and a plurality of axial grooves extending in the axial direction are formed in external surfaces of the second bearing 52 and the third bearing 53. The radial grooves and the axial grooves serve as communication passages that allow oil to flow through the second bearing 52 and the third bearing 53 when two members are contacted in the axial direction via the second bearing 52 and the third bearing 53.

In the embodiment, the second bearing 52 is positioned in the radial direction by an axially retracted surface 41 a formed to be continuous from a surface of the one-side radially extending portion 41, to be discussed later, on the other side in the axial direction. That is, the second bearing 52 is fixed with the outer peripheral surface of the second bearing 52 fitted with the axially retracted surface 41 a, which positions the second bearing 52 in the radial direction. Meanwhile, the third bearing 53 is positioned in the radial direction by a radially outer end of the flange portion 11. That is, the third bearing 53 is fixed with the inner peripheral surface of the third bearing 53 fitted with the outer peripheral surface of a portion of the flange portion 11 on the other side in the axial direction with respect to the notched groove 11 a, which positions the third bearing 53 in the radial direction.

As shown in FIGS. 2 and 3, the hybrid drive device 1 according to the embodiment further includes the clutch housing CH which houses the clutch CL. The clutch housing CH is disposed across the input shaft I and the intermediate shaft M so as to be relatively rotatable with respect to the input shaft I and rotatable together with the intermediate shaft M. The clutch housing CH houses the clutch CL by covering both sides of the clutch CL in the axial direction and the outer side of the clutch CL in the radial direction on the radially outer side of the input shaft I and the intermediate shaft M, which are disposed coaxially with each other. Therefore, the clutch housing CH includes the one-side radially extending portion 41 disposed on one side in the axial direction with respect to the clutch CL to extend radially, the other-side radially extending portion 45 disposed on the other side in the axial direction with respect to the clutch CL to extend radially, and a cylindrical portion 49 that couples respective radially outer end portions of the one-side radially extending portion 41 and the other-side radially extending portion 45 to each other in the axial direction.

The one-side radially extending portion 41 is shaped to extend at least in the radial direction. In the embodiment, the one-side radially extending portion 41 extends in the radial direction and the circumferential direction. A through hole in the axial direction is formed in a radially central portion of the one-side radially extending portion 41, and the input shaft I, which is inserted through the through hole, penetrates through the one-side radially extending portion 41 to be inserted into the clutch housing CH. The one-side radially extending portion 41 is coupled to the axially projecting portion 42 which has the shape of a cylinder (boss) projecting toward one side in the axial direction. The axially projecting portion 42 is formed to surround the circumference of the input shaft I. A fifth bearing 55 is disposed between the axially projecting portion 42 and the input shaft I. The axially projecting portion 42 is integrally coupled to the one-side radially extending portion 41 at a radially inner end portion of the one-side radially extending portion 41. In the embodiment, the one-side radially extending portion 41 is a member having a curved shape like a dish that is convex toward the other side in the axial direction such that a radially inner portion is positioned on the other side in the axial direction with respect to a radially outer portion as a whole. The one-side radially extending portion 41 is disposed adjacently with a predetermined clearance on the other side in the axial direction with respect to the first support wall 4. The axially projecting portion 42 is disposed adjacently with a predetermined clearance on the radially inner side with respect to the axially projecting portion 5 of the first support wall 4. Further, the one-side radially extending portion 41 is disposed adjacently with a predetermined clearance on one side in the axial direction with respect to the clutch hub 21 and the flange portion 11 of the input shaft I. The first bearing 51 and the first seal member 61, which suppresses leakage of oil to the other side in the axial direction (to the side of the rotary electric machine MG) by liquid-tightly sealing an area between the axially projecting portion 42 and the axially projecting portion 5 of the first support wall 4, are disposed across the axially projecting portion 42 and the axially projecting portion 5. In the embodiment, the axially projecting portion 42 is equivalent to the “second axially projecting portion” according to the present invention. In addition, the first bearing 51 is equivalent to the “first support mechanism” according to the present invention, and the first seal member 61 is equivalent to the “first seal mechanism” according to the present invention.

In the embodiment, the one-side radially extending portion 41 includes the cylindrical axially retracted surface 41 a foamed to be continuous from a surface of the one-side radially extending portion 41 on the other side in the axial direction and to be retracted toward one side in the axial direction. The axially retracted surface 41 a is formed at a radially inner end portion of the one-side radially extending portion 41. As discussed above, the second bearing 52 is positioned in the radial direction by the axially retracted surface 41 a.

The cylindrical portion 49 has the shape of a cylinder extending in the axial direction and the circumferential direction to cover the radially outer side of the clutch CL. The cylindrical portion 49 couples respective radially outer end portions of the one-side radially extending portion 41 and the other-side radially extending portion 45 to each other in the axial direction. In the embodiment, the cylindrical portion 49 extends from a radially outer end portion of the one-side radially extending portion 41 toward the other side in the axial direction. In the embodiment, the cylindrical portion 49 is formed integrally with the one-side radially extending portion 41.

The other-side radially extending portion 45 is shaped to extend at least in the radial direction. In the embodiment, the other-side radially extending portion 45 extends in the radial direction and the circumferential direction. In the embodiment, the other-side radially extending portion 45 is a plate member having a shape in which a radially inner portion is offset toward one side in the axial direction with respect to a radially outer portion such that the radially inner portion is positioned on one side in the axial direction with respect to the radially outer portion as a whole. The other-side radially extending portion 45 is coupled by welding or the like to a portion of the cylindrical portion 49 on the other side in the axial direction in the vicinity of a radially outer end portion of the other-side radially extending portion 45. A through hole in the axial direction is formed in a radially central portion of the other-side radially extending portion 45, and the intermediate shaft M, which is inserted through the through hole, penetrates through the other-side radially extending portion 45 to be inserted into the clutch housing CH. The inner peripheral surface of a radially inner end portion of the other-side radially extending portion 45 contacts the outer peripheral surface of the intermediate shaft M over the entire circumference. The other-side radially extending portion 45 is coupled to an axially projecting portion 46 which has the shape of a cylinder (boss) projecting toward the other side in the axial direction. The axially projecting portion 46 is formed to surround the circumference of the intermediate shaft M. The axially projecting portion 46 is integrally coupled to the other-side radially extending portion 45 at a radially inner end portion of the other-side radially extending portion 45. In the embodiment, the axially projecting portion 46 is equivalent to the “fourth axially projecting portion” according to the present invention.

The axially projecting portion 46 is splined to the intermediate shaft M to rotate together with the intermediate shaft M. The other-side radially extending portion 45 is disposed adjacently with a predetermined clearance on one side in the axial direction with respect to the second support wall 7. The axially projecting portion 46 is disposed adjacently with a predetermined clearance on the radially inner side with respect to the axially projecting portion 8 of the second support wall 7. Further, the other-side radially extending portion 45 is disposed adjacently with a predetermined clearance on the other side in the axial direction with respect to the clutch hub 21 and the flange portion 11 of the input shaft I at a radially inner portion of the other-side radially extending portion 45. A fourth bearing 54 and a second seal member 62, which suppresses leakage of oil to one side in the axial direction (to the side of the rotary electric machine MG) by liquid-tightly sealing an area between the axially projecting portion 46 and the axially projecting portion 8 of the second support wall 7, are disposed across the axially projecting portion 46 and the axially projecting portion 8. In the embodiment, the fourth bearing 54 is equivalent to the “second support mechanism” according to the present invention, and the second seal member 62 is equivalent to the “second seal mechanism” according to the present invention.

In the embodiment, the clutch drum 26 is formed integrally with the other-side radially extending portion 45. More specifically, the cylindrical clutch drum 26 is integrally formed to extend from the other-side radially extending portion toward one side in the axial direction in the vicinity of a radially outer end portion of the other-side radially extending portion 45. In this event, the clutch drum 26 is disposed adjacently with a predetermined clearance from the cylindrical portion 49 in the radial direction on the radially inner side with respect to the cylindrical portion 49. The gap formed between the clutch drum 26 and the cylindrical portion 49 opens in the axial direction at an end portion on one side in the axial direction in the clutch housing CH. In the embodiment, the hydraulic oil chamber 37 is formed between the other-side radially extending portion 45 and the piston 36. The oil communication passage 48, which extends radially as a whole with slight inclination toward one side in the axial direction with respect to the radial direction to communicate the oil supply passage 15 and the hydraulic oil chamber 37 with each other, is formed in the other-side radially extending portion 45 at a portion where the other-side radially extending portion 45 is coupled to the axially projecting portion 46.

In the clutch housing CH according to the embodiment, as described above, the one-side radially extending portion 41 on one side in the axial direction is configured such that a radially inner portion is positioned on the other side in the axial direction with respect to a radially outer portion as a whole, and includes the axially projecting portion 42 projecting toward one side in the axial direction from a radially inner end portion of the one-side radially extending portion 41. In addition, the other-side radially extending portion 45 on the other side in the axial direction is configured such that a radially inner portion is positioned on one side in the axial direction with respect to a radially outer portion as a whole, and includes the axially projecting portion 46 projecting toward the other side in the axial direction from a radially inner end portion of the other-side radially extending portion 45. Accordingly, the clutch housing CH is formed in a generally Ω-shape as a whole in cross section taken along a plane including the axial direction and the radial direction. The term “Q-shape” as used hereinafter likewise refers to a shape in cross section taken along a plane including the axial direction and the radial direction.

Of the space formed inside the clutch housing CH, most of the space excluding the hydraulic oil chamber 37 serves as the oil circulation chamber 38 described earlier. In the embodiment, oil discharged from the oil pump 18 and adjusted to a predetermined hydraulic pressure is supplied to the oil circulation chamber 38 via the oil circulation passage 47 formed to extend in the axial direction in the axially projecting portion 46. In the embodiment, the fifth bearing 55 disposed between the axially projecting portion 42 and the input shaft I is a bearing with a sealing function (here, a needle bearing with a seal ring) configured to secure a certain degree of liquid tightness. Further, the inner peripheral surface of a radially inner end portion of the other-side radially extending portion 45 contacts the outer peripheral surface of the intermediate shaft M over the entire circumference. Therefore, when oil is supplied to the oil circulation chamber 38 via the oil circulation passage 47, the oil circulation chamber 38 in the clutch housing CH is basically always filled with oil. Thus, in the hybrid drive device 1 according to the embodiment, the plurality of friction plates 31 provided in the clutch CL can be cooled effectively with a large amount of oil always filling the oil circulation chamber 38. In the embodiment, the oil circulation chamber 38 is equivalent to the “oil chamber” according to the present invention.

While the oil circulation chamber 38 is basically always filled with oil, oil flows through the oil circulation chamber 38. The flow of oil is indicated by the broken arrows in FIGS. 2 and 3. That is, oil supplied from the oil circulation passage 47 to the oil circulation chamber 38 first flows radially outward through an area between the other-side radially extending portion 45 and the flange portion 11 and an area between the piston 36 and the clutch hub 21 to cool the plurality of friction plates 31. Oil also flows radially inward through an area between the clutch hub 21 and the flange portion 11 and the one-side radially extending portion 41 to reach the base end portion of the flange portion 11. Thereafter, oil is discharged from the oil circulation chamber 38. While oil may flow in the circumferential direction at the same time as a matter of course, the main flow of oil in the radial direction and the axial direction is as described above.

In the embodiment, as shown in FIG. 2, there are two systems of discharge paths for oil from the oil circulation chamber 38. A first discharge path passes via a communication hole in the radial direction opening in the outer peripheral surface of the input shaft I and the oil discharge passage 16 formed in a radially inner portion of the intermediate shaft M. In the embodiment, the outside diameter of an end portion of the intermediate shaft M on one side in the axial direction is fowled to be slightly smaller than the inside diameter of the axial end hole portion 12 of the input shaft I, and a predetermined gap is formed between an end surface of the intermediate shaft M on one side in the axial direction and a surface defining the bottom portion of the axial end hole portion 12 of the input shaft I in the axial direction. This enables oil discharged from the oil circulation chamber 38 through the communication hole in the radial direction formed in the input shaft I to be appropriately guided to the oil discharge passage 16 via a radial gap and an axial gap formed between the intermediate shaft M and the axial end hole portion 12 of the input shaft I. A second discharge path is provided for oil leaking out from the fifth bearing 55 in the axial direction, and passes via the oil discharge passage 72 inside the oil passage forming member 71 attached to the first support wall 4. The second discharge path is defined by the third seal member 63 disposed between the input shaft I and the first support wall 4 and the first seal member 61 disposed between the axially projecting portion 42 of the clutch housing CH and the axially projecting portion 5 of the first support wall 4. This enables the oil leaking out from the fifth bearing 55 in the axial direction to be appropriately guided to the oil discharge passage 72.

As shown in FIG. 2, the rotary electric machine MG is disposed radially outwardly of the clutch housing CH. The rotary electric machine MG includes the stator St fixed to the case 2 and the rotor Ro supported radially inwardly of the stator St so as to be rotatable. The stator St includes a stator core fixed to the first support wall 4 and formed as a laminated structure in which a plurality of magnetic steel sheets each formed in an annular plate shape are laminated on each other, and a coil wound around the stator core. Portions of the coil that project from both sides of the stator core in the axial direction are coil end portions Ce. The rotor Ro of the rotary electric machine MG includes a rotor core formed as a laminated structure in which a plurality of magnetic steel sheets each formed in an annular plate shape are laminated on each other, and permanent magnets embedded in the rotor core.

In the embodiment, the rotary electric machine MG is disposed to overlap the clutch housing CH in the axial direction. That is, the rotary electric machine MG is disposed to overlap the clutch housing CH as seen from the radial direction (in regard to the arrangement of two members; the same applies hereinafter). In the embodiment, in particular, the rotor Ro of the rotary electric machine MG is fixed to the outer peripheral portion of the cylindrical portion 49 forming the clutch housing CH. That is, the rotor Ro is fixed to the cylindrical portion 49 with the respective inner peripheral surfaces of the plurality of magnetic steel sheets forming the rotor Ro contacting the outer peripheral surface of the cylindrical portion 49. This allows the clutch housing CH to also function as a rotor support member that supports the rotor Ro. In the embodiment, the clutch housing CH and the rotor support member are formed as a common component.

In the embodiment, a rotation sensor 19 is provided on the other side in the axial direction with respect to the clutch housing CH and adjacent to both the second support wall 7 of the case 2 and the other-side radially extending portion 45. The rotation sensor 19 is a sensor that detects the rotation phase of the rotor Ro with respect to the stator St of the rotary electric machine MG. In the embodiment, the rotation sensor 19 is disposed radially outwardly of the oil pump 18 housed inside the second support wall 7 to overlap the oil pump 18 in the axial direction. In the embodiment, a sensor stator of the rotation sensor 19 is fixed to the second support wall 7, and a sensor rotor of the rotation sensor 19 is fixed to the inner peripheral surface of an end portion of the cylindrical portion 49 on the other side in the axial direction. A resolver or the like, for example, may be used as the rotation sensor 19.

In the embodiment, the damper D is disposed with a predetermined gap on one side in the axial direction with respect to the first support wall 4. The damper D is disposed in a space formed by retracting the first support wall 4, which is formed to have a curved shape like a dish that is convex toward the other side in the axial direction, toward the other side in the axial direction from one side in the axial direction. In the embodiment, further, the damper D is disposed radially inwardly of the coil end portion Ce of the stator St of the rotary electric machine MG on one side in the axial direction (on the side of the internal combustion engine E) to overlap the coil end portion Ce in the axial direction. In this way, with the coil end portion Ce and the damper D disposed to overlap each other in the axial direction, the axial dimension of the entire hybrid drive device 1 is reduced. In the embodiment, the damper D is equivalent to the “damper device” according to the present invention.

1-3. Rotatably Supporting Structure And Sealing Structure for Clutch Housing

Next, the rotatably supporting structure and the sealing structure for the clutch housing CH with respect to the case 2 according to the embodiment will be described. The rotatably supporting structure and the sealing structure according to the embodiment are roughly implemented by the first bearing 51, the fourth bearing 54, the first seal member 61, and the second seal member 62. That is, the rotatably supporting structure according to the embodiment is roughly implemented by the first bearing 51 provided on one side in the axial direction with respect to the clutch housing CH to support the clutch housing CH in the axial direction and the radial direction so as to be rotatable with respect to the case 2, and the fourth bearing 54 provided on the other side in the axial direction with respect to the clutch housing CH to support the clutch housing CH in the axial direction and the radial direction so as to be rotatable with respect to the case 2. Meanwhile, the sealing structure according to the embodiment is roughly implemented by the first seal member 61 provided on the side of the rotor Ro of the rotary electric machine MG with respect to the first bearing 51 in the direction along the clutch housing CH to oil-tightly seals an area between the case 2 and the clutch housing CH, and the second seal member 62 provided on the side of the rotor Ro of the rotary electric machine MG with respect to the fourth bearing 54 to oil-tightly seals an area between the case 2 and the clutch housing CH. The structures will be described in detail below.

As shown in FIG. 3, the clutch housing CH includes the one-side radially extending portion 41 and the axially projecting portion 42 integrally coupled to the one-side radially extending portion 41. The axially projecting portion 42 is disposed adjacently with a predetermined clearance on the radially inner side with respect to the axially projecting portion 5 of the first support wall 4. A stepped portion 42 a in the axial direction is formed on the outer peripheral surface of the axially projecting portion 42. Here, the “stepped portion in the axial direction” on the outer peripheral surface refers to a portion formed at a predetermined position of the axially projecting portion 42 in the axial direction where the outside diameter of the axially projecting portion 42 is varied. In the embodiment, the axially projecting portion 42 is formed to be smaller in diameter at a portion on one side in the axial direction with respect to the stepped portion 42 a than at a portion on the other side in the axial direction with respect to the stepped portion 42 a. That is, the axially projecting portion 42 is formed in a stepped shape in which a large diameter portion is formed on the other side in the axial direction and a small diameter portion is formed on one side in the axial direction.

The first bearing 51 is disposed between and in contact with the outer peripheral surface of the small diameter portion of the axially projecting portion 42 and the inner peripheral surface of the axially projecting portion 5 of the first support wall 4, with the first bearing 51 contacting the stepped portion 42 a from one side in the axial direction. In the embodiment, a ball bearing that can receive both a radial load and an axial load is used as the first bearing 51. In the embodiment, a relatively large ball bearing is used to precisely support the rotor Ro of the rotary electric machine MG fixed to the outer peripheral portion of the clutch housing CH. The first bearing 51 also contacts a surface of the first support wall 4 on the other side in the axial direction. This allows the one-side radially extending portion 41 forming the clutch housing CH to be supported in the radial direction and the axial direction by the first support wall 4 via the first bearing 51 so as to be rotatable. Here, in particular, the one-side radially extending portion 41 is supported in the axial direction from one side in the axial direction by the first support wall 4. The first bearing 51 is supplied with oil leaking out from the oil circulation chamber 38 in the clutch housing CH through the fifth bearing 55 in the axial direction and through a gap between the one-side radially extending portion 41 and the first support wall 4. The third seal member 63 blocks leakage of oil to one side in the axial direction (to the side of the internal combustion engine E) through an area between the input shaft I and the first support wall 4 to supply oil to the first bearing 51. This enables oil having cooled the plurality of friction plates 31 to be effectively utilized to lubricate the first bearing 51.

In the embodiment, the first seal member 61 is disposed on the other side in the axial direction with respect to the first bearing 51 and on the side of the rotor Ro of the rotary electric machine MG with respect to the first bearing 51 in the direction along the clutch housing CH formed in an Q-shape as a whole, and side by side with the first bearing 51 in the axial direction. The first seal member 61 is disposed between and in contact with the outer peripheral surface of the large diameter portion of the axially projecting portion 42 and the inner peripheral surface of the axially projecting portion 5 of the first support wall 4. The first seal member 61 suppresses leakage of oil to the side of the rotor Ro of the rotary electric machine MG (here, to the other side in the axial direction) by liquid-tightly sealing an area between the axially projecting portion 42 and the axially projecting portion 5. This prevents oil having lubricated the first bearing 51 from flowing in the direction along the clutch housing CH to reach the rotary electric machine MG. In addition, oil having lubricated the first bearing 51 can be appropriately guided to the oil discharge passage 72 formed in the oil passage forming member 71 to be discharged.

As shown in FIG. 3, the clutch housing CH includes the other-side radially extending portion 45 and the axially projecting portion 46 integrally coupled to the other-side radially extending portion 45. The axially projecting portion 46 is disposed adjacently with a predetermined clearance on the radially inner side with respect to the axially projecting portion 8 of the second support wall 7. A stepped portion 46 a in the axial direction is formed on the outer peripheral surface of the axially projecting portion 46. In the embodiment, the axially projecting portion 46 is formed to be smaller in diameter at a portion on the other side in the axial direction with respect to the stepped portion 46 a than a portion on one side in the axial direction with respect to the stepped portion 46 a. That is, the axially projecting portion 46 is formed in a stepped shape in which a large diameter portion is formed on one side in the axial direction and a small diameter portion is formed on the other side in the axial direction.

The fourth bearing 54 is disposed between and in contact with the outer peripheral surface of the small diameter portion of the axially projecting portion 46 and the inner peripheral surface of the axially projecting portion 8 of the second support wall 7, with the fourth bearing 54 contacting the stepped portion 46 a from the other side in the axial direction. In the embodiment, a ball bearing that can receive both a radial load and an axial load is used as the fourth bearing 54. In the embodiment, a relatively large ball bearing is used to precisely support the rotor Ro of the rotary electric machine MG fixed to the outer peripheral portion of the clutch housing CH. The fourth bearing 54 also contacts a surface of the second support wall 7 on one side in the axial direction. This allows the other-side radially extending portion 45 forming the clutch housing CH to be supported in the radial direction and the axial direction by the second support wall 7 via the fourth bearing 54 so as to be rotatable. Here, in particular, the other-side radially extending portion 45 is supported in the axial direction from the other side in the axial direction by the second support wall 7. The fourth bearing 54 is supplied with oil leaking out from the pump chamber which houses the oil pump 18 through an area between the second support wall 7 and the axially projecting portion 46 in the axial direction. This enables the fourth bearing 54 to be lubricated.

In the embodiment, the second seal member 62 is disposed on one side in the axial direction with respect to the fourth bearing 54 and on the side of the rotor Ro of the rotary electric machine MG with respect to the fourth bearing 54 in the direction along the clutch housing CH formed in an Ω-shape as a whole, and side by side with the fourth bearing 54 in the axial direction. The second seal member 62 is disposed between and in contact with the outer peripheral surface of the large diameter portion of the axially projecting portion 46 and the inner peripheral surface of the axially projecting portion 8 of the second support wall 7. The second seal member 62 suppresses leakage of oil to the side of the rotor Ro of the rotary electric machine MG (here, to one side in the axial direction) by liquid-tightly sealing an area between the axially projecting portion 46 and the axially projecting portion 8. This prevents oil having lubricated the fourth bearing 54 from flowing in the direction along the clutch housing CH to reach the rotary electric machine MG. In addition, oil having lubricated the fourth bearing 54 can be appropriately guided to the oil discharge passage 9 formed in the second support wall 7 to be discharged.

In the embodiment, as described above, the one-side radially extending portion 41 forming a part of the clutch housing CH is supported in the axial direction from one side in the axial direction by the first support wall 4 via the first bearing 51, and the other-side radially extending portion 45 forming another part of the clutch housing CH is supported in the axial direction from the other side in the axial direction by the second support wall 7 via the fourth bearing 54. Accordingly, the clutch housing CH can be supported from both sides in the axial direction by the first support wall 4 and the second support wall 7. Here, in the embodiment, as described above, the oil circulation chamber 38 formed in the clutch housing CH is basically always filled with oil to effectively cool the friction plates 31 of the clutch CL. Therefore, a so-called ballooning phenomenon may occur when the clutch housing CH rotates together with the intermediate shaft M, such as when the vehicle is running normally. That is, oil filling the oil circulation chamber 38 may be subjected to a centrifugal force, which may elastically deform the clutch housing CH so as to expand in the axial direction. Even in this case, it is possible to effectively suppress actual occurrence of a ballooning phenomenon and deformation of the clutch housing CH in the axial direction since the clutch housing CH is supported from both sides in the axial direction by the first support wall 4 and the second support wall 7 in the embodiment.

Further, the first seal member 61 and the second seal member 62 are disposed on the side of the rotor Ro of the rotary electric machine MG with respect to the first bearing 51 and the fourth bearing 54, respectively, in the direction along the clutch housing CH formed in an Ω-shape as a whole. This prevents oil having lubricated the first bearing 51 and the fourth bearing 54 from reaching the rotary electric machine MG. Accordingly, an air-cooling structure that utilizes a wind received while the vehicle is running or the like can be employed as a cooling structure for the rotary electric machine MG. Thus, the rotary electric machine MG which requires precise control can be cooled appropriately without being significantly affected by foreign matter or the like.

In the embodiment, the first bearing 51 is disposed to overlap the one-side radially extending portion 41 in the axial direction. More specifically, the first bearing 51 is disposed to overlap the radially outer portion of the one-side radially extending portion 41 in the axial direction. As a matter of course, the first seal member 61, which is disposed adjacently on the other side in the axial direction with respect to the first bearing 51, is also disposed to overlap the one-side radially extending portion 41 in the axial direction. The first seal member 61 is disposed to overlap the radially inner portion of the one-side radially extending portion 41 in the axial direction. In this way, in the embodiment, both the first bearing 51 and the first seal member 61 are disposed in a space formed by retracting the one-side radially extending portion 41, which is formed to have a curved shape like a dish that is convex toward the other side in the axial direction, toward the other side in the axial direction from one side in the axial direction. This allows the axial dimension of the entire device to be reduced while implementing the rotatably supporting structure and the sealing structure for the clutch housing CH with a simple configuration on one side in the axial direction with respect to the clutch housing CH.

Meanwhile, the fourth bearing 54 is disposed to overlap the other-side radially extending portion 45 in the axial direction. More specifically, the fourth bearing 54 is disposed to overlap the radially outer portion of the other-side radially extending portion 45 in the axial direction. As a matter of course, the second seal member 62, which is disposed adjacently on one side in the axial direction with respect to the fourth bearing 54, is also disposed to overlap the other-side radially extending portion 45 in the axial direction. The second seal member 62 is disposed to overlap a radially central portion of the other-side radially extending portion 45 in the axial direction. More specifically, the other-side radially extending portion 45 includes a first circular plate portion 45 a provided with the axially projecting portion 46, a second circular plate portion 45 c disposed radially outwardly of the first circular plate portion 45 a and offset on the other side in the axial direction with respect to the first circular plate portion 45 a, and a stepped cylindrical portion 45 b forming an offset portion between the first circular plate portion 45 a and the second circular plate portion 45 c to couple the first circular plate portion 45 a and the second circular plate portion 45 c to each other. The second seal member 62 is disposed to overlap the stepped cylindrical portion 45 b in the axial direction. In this way, in the embodiment, both the fourth bearing 54 and the second seal member 62 are disposed in a space formed on the other side in the axial direction with respect to the first circular plate portion 45 a offset on one side in the axial direction with respect to the second circular plate portion 45 c of the other-side radially extending portion 45. This allows the axial dimension of the entire device to be reduced while implementing the rotatably supporting structure and the sealing structure for the clutch housing CH with a simple configuration on the other side in the axial direction with respect to the clutch housing CH.

In the embodiment, as described above, the rotatably supporting structure and the sealing structure for the clutch housing CH with respect to the case 2 are implemented with all of the first bearing 51, the fourth bearing 54, the first seal member 61, and the second seal member 62 disposed without significantly projecting in the axial direction from a space occupied by the clutch housing CH in the axial direction. In addition, in the embodiment, as described above, the rotor Ro of the rotary electric machine MG is fixed to the outer peripheral portion of the cylindrical portion 49 forming the clutch housing CH to overlap the clutch housing CH in the axial direction. Accordingly, the axial dimension of the entire hybrid drive device 1 can be reduced by compactly disposing the clutch housing CH and the clutch CL, the rotary electric machine MG, and the plurality of bearings 51 and 54 and seal members 61 and 62 housed in the clutch housing CH in a space occupied by the clutch housing CH in the axial direction. Further, in the embodiment, as described above, oil discharged from the oil circulation chamber 38 is supplied to the first bearing 51 to lubricate the first bearing 51. With such a configuration, it is not necessary to provide a dedicated oil passage for lubricating the first bearing 51. Accordingly, the axial dimension of the entire hybrid drive device 1 can also be reduced from this point, which improves the mountability of the hybrid drive device 1 on vehicles.

In the embodiment, the first bearing 51, the first seal member 61, the fourth bearing 54, and the second seal member 62 are disposed to overlap each other in the radial direction. That is, these components are disposed to overlap each other as seen from the axial direction (in regard to the arrangement of two members; the same applies hereinafter). The second bearing 52 and the third bearing 53 are disposed to overlap one or two or more of the first bearing 51, the first seal member 61, the fourth bearing 54, and the second seal member 62 in the radial direction in an area between the first bearing 51 and the first seal member 61 and the fourth bearing 54 and the second seal member 62 in the axial direction. The plurality of friction plates 31 of the clutch CL are disposed radially outwardly of not only the first bearing 51, the second bearing 52, the third bearing 53, the fourth bearing 54, the first seal member 61, and the second seal member 62, which have been mentioned above, but also the fifth bearing 55. The plurality of friction plates 31 are disposed to overlap at least the second bearing 52, the third bearing 53, and the second seal member 62 in the axial direction. In the embodiment, further, the second seal member 62, of these components, is disposed to overlap the piston 36 in the axial direction.

2. Second Embodiment

A second embodiment of the present invention will be described with reference to the drawings. The overall configuration of the hybrid drive device 1 according to the embodiment and the configuration of respective sections of the hybrid drive device 1 are basically the same as those in the above first embodiment. In the embodiment, however, the arrangement of the rotatably supporting structure and the sealing structure for the clutch housing CH with respect to the case 2 on the other side in the axial direction with respect to the clutch housing CH is partially different from that in the above first embodiment. Thus, the differences from the above first embodiment will be mainly described in detail below. The same elements as those in the above first embodiment will not be specifically described.

In the embodiment, as shown in FIG. 4, no stepped portion in the axial direction (the stepped portion 46 a in the above first embodiment; see FIG. 3) is formed on the outer peripheral surface of the axially projecting portion 46, and the axially projecting portion 46 is formed to have substantially the same diameter over the entire length in the axial direction. The fourth bearing 54 is disposed between and in contact with the outer peripheral surface of the axially projecting portion 46 and the inner peripheral surface of the axially projecting portion 8 of the second support wall 7, with the fourth bearing 54 contacting the first circular plate portion 45 a of the other-side radially extending portion 45 from the other side in the axial direction. In the embodiment, a ball bearing that can receive both a radial load and an axial load is used as the fourth bearing 54. The fourth bearing 54 also contacts a surface of the second support wall 7 on one side in the axial direction. This allows the other-side radially extending portion 45 forming the clutch housing CH to be supported in the radial direction and the axial direction by the second support wall 7 via the fourth bearing 54 so as to be rotatable. Here, in particular, the other-side radially extending portion 45 is supported in the axial direction from the other side in the axial direction by the second support wall 7. The fourth bearing 54 is supplied with oil leaking out from the pump chamber which houses the oil pump 18 through an area between the second support wall 7 and the axially projecting portion 46 in the axial direction. This enables the fourth bearing 54 to be lubricated.

In the embodiment, the second seal member 62 is disposed on the radially outer side with respect to the fourth bearing 54 and on the side of the rotor Ro of the rotary electric machine MG with respect to the fourth bearing 54 in the direction along the clutch housing CH formed in an Ω-shape as a whole, and to overlap the fourth bearing 54 in the axial direction. The second seal member 62 is disposed between and in contact with the outer peripheral surface of the axially projecting portion 8 of the second support wall 7 and the inner peripheral surface of the stepped cylindrical portion 45 b of the other-side radially extending portion 45. With such an arrangement, the fourth bearing 54 and the second seal member 62, which are disposed to overlap each other in the axial direction, are also disposed to overlap the other-side radially extending portion 45 in the axial direction. More specifically, both the fourth bearing 54 and the second seal member 62 are disposed to overlap the stepped cylindrical portion 45 b of the other-side radially extending portion 45 in the axial direction. The second seal member 62 suppresses leakage of oil to the side of the rotor Ro of the rotary electric machine MG by liquid-tightly sealing an area between the stepped cylindrical portion 45 b and the axially projecting portion 8.

Also in the embodiment, the rotatably supporting structure and the sealing structure for the clutch housing CH with respect to the case 2 are implemented with all of the first bearing 51, the fourth bearing 54, the first seal member 61, and the second seal member 62 disposed without significantly projecting in the axial direction from a space occupied by the clutch housing CH in the axial direction. Also in the embodiment, in addition, the rotor Ro of the rotary electric machine MG is fixed to the outer peripheral portion of the cylindrical portion 49 forming the clutch housing CH to overlap the clutch housing CH in the axial direction. Accordingly, the axial dimension of the entire hybrid drive device 1 can be reduced by compactly disposing the clutch housing CH and the clutch CL, the rotary electric machine MG, and the plurality of bearings 51 and 54 and seal members 61 and 62 housed in the clutch housing CH in a space occupied by the clutch housing CH in the axial direction. Also in the embodiment, further, oil discharged from the oil circulation chamber 38 is supplied to the first bearing 51 to lubricate the first bearing 51. Accordingly, it is not necessary to provide a dedicated oil passage for lubricating the first bearing 51, and the axial dimension of the entire hybrid drive device 1 can also be reduced from this point.

In the embodiment, the first bearing 51, the first seal member 61, and the second seal member 62 are disposed to overlap each other in the radial direction. In addition, the second bearing 52, the third bearing 53, the fourth bearing 54, and the fifth bearing 55 are disposed to overlap each other in the radial direction. The second bearing 52 and the third bearing 53 are disposed side by side across the flange portion 11 on both sides of the flange portion 11 in the axial direction. In the embodiment, a thrust bearing that can receive an axial load is used as each of the second bearing 52 and the third bearing 53. The second bearing 52 is positioned in the radial direction by the axially retracted surface 41 a, which is formed to be continuous from a surface of the one-side radially extending portion 41 on the other side in the axial direction, and the input shaft I. That is, the second bearing 52 is fixed with the outer peripheral surface of the second bearing 52 fitted with the axially retracted surface 41 a and the inner peripheral surface of the second bearing 52 contacting the outer peripheral surface of the input shaft I, which positions the second bearing 52 in the radial direction. The third bearing 53 is positioned in the radial direction by an axially retracted surface 45 d, which is formed to be continuous from a surface of the other-side radially extending portion 45 on one side in the axial direction, and the input shaft I. That is, the third bearing 53 is fixed with the outer peripheral surface of the third bearing 53 fitted with the axially retracted surface 45 d and the inner peripheral surface of the third bearing 53 contacting the outer peripheral surface of the input shaft I, which positions the third bearing 53 in the radial direction.

3. Other Embodiments

Finally, hybrid drive devices according to other embodiments of the present invention will be described. A characteristic configuration disclosed in each of the following embodiments may be applied not only to that particular embodiment but also in combination with a characteristic configuration disclosed in any other embodiment unless any contradiction occurs.

(1) In each of the above embodiments, both the first bearing 51 and the first seal member 61 are disposed to overlap the one-side radially extending portion 41 in the axial direction. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, for example, only the first seal member 61 disposed on the other side in the axial direction, of the first bearing 51 and the first seal member 61, is disposed to overlap the one-side radially extending portion 41 in the axial direction. In an alternative suitable embodiment of the present invention, both the first bearing 51 and the first seal member 61 are disposed further on one side in the axial direction with respect to the one-side radially extending portion 41 without overlapping the one-side radially extending portion 41 in the axial direction. Also in these cases, the rotatably supporting structure and the sealing structure for the clutch housing CH with respect to the case 2 can be appropriately implemented at least on one side in the axial direction.

(2) In each of the above embodiments, both the fourth bearing 54 and the second seal member 62 are disposed to overlap the other-side radially extending portion 45 in the axial direction. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, in the case where the second seal member 62 is disposed on one side in the axial direction with respect to the fourth bearing 54, for example, as in the above first embodiment, only the second seal member 62 may be disposed to overlap the other-side radially extending portion 45 in the axial direction. In an alternative suitable embodiment of the present invention, both the fourth bearing 54 and the second seal member 62 are disposed further on the other side in the axial direction with respect to the other-side radially extending portion 45 without overlapping the other-side radially extending portion 45 in the axial direction. Also in these cases, the rotatably supporting structure and the sealing structure for the clutch housing CH with respect to the case 2 can be appropriately implemented at least on the other side in the axial direction.

(3) In the above second embodiment, the fourth bearing 54 and the second seal member 62 are disposed to overlap each other in the axial direction. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, the second seal member 62 may be displaced toward one side in the axial direction or toward the other side in the axial direction with respect to the fourth bearing 54 without overlapping the fourth bearing 54 in the axial direction, as long as the second seal member 62 is disposed on the radially outer side with respect to the fourth bearing 54 and at least on the side of the rotor Ro of the rotary electric machine MG with respect to the fourth bearing 54 in the direction along the clutch housing CH.

(4) In each of the above embodiments, the second seal member 62 is disposed to overlap the piston 36 of the clutch CL in the axial direction. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, the second seal member 62 is displaced toward one side in the axial direction or toward the other side in the axial direction with respect to the piston 36 without overlapping the piston 36 in the axial direction.

(5) In each of the above embodiments, the notched groove 11 a is formed at an end portion of the flange portion 11, which forms a part of the coupling member, on the outer side in the radial direction and on one side in the axial direction, and the annular plate portion 22 is coupled to the flange portion 11 with the annular plate portion 22 in contact with the notched groove 11 a from one side in the axial direction. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, for example, a notched groove is formed at an end portion of the flange portion 11 on the outer side in the radial direction and on the other side in the axial direction, and the annular plate portion 22 is coupled to the flange portion 11 with the annular plate portion 22 in contact with the notched groove from the other side in the axial direction. In an alternative suitable embodiment of the present invention, a notched groove is formed at an end portion of the annular plate portion 22, which forms another part of the coupling member on the inner side in the radial direction, and the flange portion 11 is coupled to the notched groove.

(6) In each of the above embodiments, the one-side radially extending portion 41 includes the cylindrical axially retracted surface 41 a formed to be continuous from a surface of the one-side radially extending portion 41 on the other side in the axial direction and to be retracted toward one side in the axial direction, and the second bearing 52 is positioned in the radial direction by the axially retracted surface 41 a. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, for example, the one-side radially extending portion 41 includes a cylindrical axially projecting portion formed to project from a surface of the one-side radially extending portion 41 on the other side in the axial direction toward the other side in the axial direction, and the second bearing 52 is positioned in the radial direction by the axially projecting portion.

(7) In each of the above embodiments, the damper D is disposed to overlap the coil end portion Ce of the stator St of the rotary electric machine MG on one side in the axial direction. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, the damper D is displaced toward one side in the axial direction with respect to the coil end portion Ce of the stator St of the rotary electric machine MG on one side in the axial direction without overlapping the coil end portion Ce in the axial direction.

(8) In each of the above embodiments, both the first support mechanism and the second support mechanism are formed using a ball bearing serving as the first bearing 51 and the second bearing 52, respectively. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, one or both of the first support mechanism and the second support mechanism may be formed by a combination of a radial bearing that can receive a radial load, such as a needle bearing, and a thrust bearing that can receive an axial load, such as a thrust bearing, for example, as long as a mechanism that can receive both a radial load and an axial load is provided.

(9) In the above first embodiment, a thrust washer is used as each of the second bearing 52 and the third bearing 53. In the above second embodiment, on the other hand, a thrust bearing is used as each of the second bearing 52 and the third bearing 53. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, a thrust washer may be used as one of the second bearing 52 and the third bearing 53, and a thrust bearing may be used as the other, because these components are only required to receive at least an axial load.

(10) In each of the above embodiments, the clutch hub 21 is drivably coupled to the input shaft I to rotate together with the input shaft I, and the clutch drum 26 is drivably coupled to the intermediate shaft M to rotate together with the intermediate shaft M. However, the present invention is not limited thereto. That is, in one suitable embodiment of the present invention, the relationship of drivable coupling of the clutch hub 21 and the clutch drum 26 to the input shaft I and the intermediate shaft M is changed, and the clutch hub 21 is drivably coupled to the intermediate shaft M to rotate together with the intermediate shaft M, and the clutch drum 26 is drivably coupled to the input shaft Ito rotate together with the input shaft I.

(11) Also regarding other configurations, the embodiments disclosed herein are illustrative in all respects, and the present invention is not limited to such embodiments. That is, it is a matter of course that a configuration obtained by appropriately altering part of a configuration not disclosed in the claims of the present invention also falls within the technical scope of the present invention as long as the obtained configuration includes a configuration disclosed in the claims or a configuration equivalent thereto.

The present invention is suitably applicable to a hybrid drive device including a first shaft drivably coupled to an internal combustion engine, a rotary electric machine, a second shaft disposed coaxially with the first shaft and drivably coupled to the rotary electric machine and a speed change mechanism, a clutch provided to switch on and off transfer of a drive force between the first shaft and the second shaft, and a case that houses the first shaft, the second shaft, the rotary electric machine, and the clutch. 

1. A hybrid drive device comprising: a first shaft drivably coupled to an internal combustion engine; a rotary electric machine; a second shaft disposed coaxially with the first shaft and drivably coupled to the rotary electric machine and a speed change mechanism; a clutch provided to switch on and off transfer of a drive force between the first shaft and the second shaft; a case that houses the first shaft, the second shaft, the rotary electric machine, and the clutch; a clutch housing which houses the clutch by covering both sides of the clutch in an axial direction and an outer side of the clutch in a radial direction, which is drivably coupled to the second shaft, and inside which an oil chamber filled with oil is formed; and a first support mechanism that supports the clutch housing in the radial direction and the axial direction so as to be rotatable with respect to the case, and a first seal mechanism that oil-tightly seals an area between the case and the clutch housing, the first support mechanism and the first seal mechanism being provided on one side in the axial direction with respect to the clutch housing, wherein a rotor of the rotary electric machine is fixed to an outer peripheral portion of the clutch housing, the case includes a one-side support wall portion provided on one side in the axial direction with respect to the clutch housing to extend radially, and a cylindrical first axially projecting portion projecting from the one-side support wall portion toward the other side in the axial direction, the clutch housing includes a one-side radially extending portion disposed on one side in the axial direction with respect to the clutch to extend radially, and a cylindrical second axially projecting portion projecting from the one-side radially extending portion toward one side in the axial direction, the second axially projecting portion is formed in a stepped shape in which a large diameter portion is formed on the other side in the axial direction and a small diameter portion is formed on one side in the axial direction, the first support mechanism is disposed in contact with an outer peripheral surface of the small diameter portion of the second axially projecting portion and an inner peripheral surface of the first axially projecting portion, and the first seal mechanism is disposed in contact with an outer peripheral surface of the large diameter portion of the second axially projecting portion and the inner peripheral surface of the first axially projecting portion, and side by side with the first support mechanism in the axial direction.
 2. The hybrid drive device according to claim 1, wherein the one-side radially extending portion is formed in a shape in which a radially inner end portion is positioned on the other side in the axial direction with respect to a radially outer end portion, and one or both of the first support mechanism and the first seal mechanism are disposed to overlap the one-side radially extending portion in the axial direction.
 3. The hybrid drive device according to claim 1, further comprising a second support mechanism that supports the clutch housing in the radial direction and the axial direction so as to be rotatable with respect to the case, and a second seal mechanism that oil-tightly seals an area between the case and the clutch housing, the second support mechanism and the second seal mechanism being provided on the other side in the axial direction with respect to the clutch housing, wherein the case includes an other-side support wall portion provided on the other side in the axial direction with respect to the clutch housing to extend radially, and a cylindrical third axially projecting portion projecting from the other-side support wall portion toward one side in the axial direction, the clutch housing includes an other-side radially extending portion disposed on the other side in the axial direction with respect to the clutch to extend radially, and a cylindrical fourth axially projecting portion projecting from the other-side radially extending portion toward the other side in the axial direction, the fourth axially projecting portion is formed in a stepped shape in which a large diameter portion is formed on one side in the axial direction and a small diameter portion is formed on the other side in the axial direction, the second support mechanism is disposed in contact with an outer peripheral surface of the small diameter portion of the fourth axially projecting portion and an inner peripheral surface of the third axially projecting portion, and the second seal mechanism is disposed in contact with an outer peripheral surface of the large diameter portion of the fourth axially projecting portion and the inner peripheral surface of the third axially projecting portion, and side by side with the second support mechanism in the axial direction.
 4. The hybrid drive device according to claim 3, wherein the other-side radially extending portion is formed in a shape in which a radially inner end portion is positioned on one side in the axial direction with respect to a radially outer end portion, and one or both of the second support mechanism and the second seal mechanism are disposed to overlap the other-side radially extending portion in the axial direction.
 5. The hybrid drive device according to claim 1, further comprising a second support mechanism that supports the clutch housing in the radial direction and the axial direction so as to be rotatable with respect to the case, and a second seal mechanism that oil-tightly seals an area between the case and the clutch housing, the second support mechanism and the second seal mechanism being provided on the other side in the axial direction with respect to the clutch housing, wherein the case includes an other-side support wall portion provided on the other side in the axial direction with respect to the clutch housing to extend radially, and a cylindrical third axially projecting portion projecting from the other-side support wall portion toward one side in the axial direction, the clutch housing includes an other-side radially extending portion disposed on the other side in the axial direction with respect to the clutch to extend radially, and a cylindrical fourth axially projecting portion projecting from the other-side radially extending portion toward the other side in the axial direction, the other-side radially extending portion includes a first circular plate portion provided with the fourth axially projecting portion, a second circular plate portion disposed radially outwardly of the first circular plate portion and offset on the other side in the axial direction with respect to the first circular plate portion, and a stepped cylindrical portion formed to couple the first circular plate portion and the second circular plate portion to each other, the second support mechanism is disposed in contact with an outer peripheral surface of the fourth axially projecting portion and an inner peripheral surface of the third axially projecting portion, and the second seal mechanism is disposed in contact with an outer peripheral surface of the third axially projecting portion and an inner peripheral surface of the stepped cylindrical portion to overlap the second support mechanism in the axial direction.
 6. The hybrid drive device according to claim 3, wherein a plurality of friction plates provided in the clutch are disposed radially outwardly of the first seal mechanism and the second seal mechanism.
 7. The hybrid drive device according to claim 6, wherein the clutch includes a piston that presses the plurality of friction plates, and the second seal mechanism is disposed to overlap the piston in the axial direction.
 8. The hybrid drive device according to claim 1, further comprising a coupling member extending radially to couple the first shaft and a clutch hub of the clutch to each other, and a third support mechanism and a fourth support mechanism disposed in contact with a surface of the coupling member on one side in the axial direction and a surface of the coupling member on the other side in the axial direction, respectively, to support the coupling member and the clutch housing so as to be relatively rotatable with respect to each other, wherein the coupling member includes a shaft-side coupling portion extending radially outward from the first shaft, and a hub-side coupling portion forming a part of the clutch hub and extending radially inward, the hub-side coupling portion is coupled to the shaft-side coupling portion with the hub-side coupling portion in contact with a notched groove formed in a radially outer end portion of the shaft-side coupling portion from one side in the axial direction, the one-side radially extending portion includes a cylindrical axially retracted surface formed to be continuous from a surface of the one-side radially extending portion on the other side in the axial direction and to be retracted toward one side in the axial direction, the third support mechanism is positioned in the radial direction by the axially retracted surface, and the fourth support mechanism is disposed radially outwardly of the third support mechanism, and positioned in the radial direction by a radially outer end of the shaft-side coupling portion.
 9. The hybrid drive device according to claim 1, further comprising a damper device disposed on one side in the axial direction with respect to the one-side support wall portion and interposed between the first shaft and the internal combustion engine, wherein the damper device is disposed to overlap in the axial direction a coil end portion projecting in the axial direction from a stator of the rotary electric machine.
 10. The hybrid drive device according to claim 5, wherein a plurality of friction plates provided in the clutch are disposed radially outwardly of the first seal mechanism and the second seal mechanism.
 11. The hybrid drive device according to claim 10, wherein the clutch includes a piston that presses the plurality of friction plates, and the second seal mechanism is disposed to overlap the piston in the axial direction. 